AN553 – Analysis of cement samples by thermogravimetry coupled with FTIR spectrometry

INTRODUCTION

The aim of these analysis is to identify the evolve gas from a cement sample by thermogravimetry coupled with FTIR spectrometry.

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EXPERIMENTAL

Experiments were conducted on a Setsys TG-DSC with the outlet of the balance connected to a Nicolet 380 IR spectrometer by heated connection part (maximum at 200°C). The cement sample, previously attacked by HCl to remove its content in carbonate, was analyzed into a platinum container under air flow at a scan rate of 20 K/min from ambient temperature up to 1100°C.

The experimental conditions of FTIR spectrometer were:

  • Scan numbers: 32 ;
  • Resolution: 4 cm-1 ;
  • Spectral domain: 4000 – 400 cm-1.

A blank is carried out in the same conditions and results provided have been corrected from this blank.

RESULTS

At 22 min, we observe a decrease of the mass, two exothermic peaks and an increase of the IR intensity. Thanks to a library, we can associate this variation mass to the loss of SO2. In the same way, at 31 minutes, we note a big decrease of the mass, an exothermic peak and an increase of the IR intensity. This variation mass corresponds to the loss of CO2 and water.

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